A braking system which is operated in accordance with such a process is often called a "deceleration-regulated braking system."
The term "brake" is used herein as a collective term for all components participating in the production of a braking force. This also applies to the terms "front axle brake" and "rear axle brake", as used herein.
A braking system process of the type mentioned above is described as a "simplification" in DE 41 42 670 A1 (U.S. Pat. No. 5,338,106, at column 5, line 58), which are incorporated herein by reference.
This process presupposes the generation of a load signal by means of a load sensor. A load sensor, however, especially in combination with the appertaining installation parts, represents a considerable cost. A load sensor also requires a considerable amount of space, especially in combination with its installation parts. It may also be prone to malfunctions, especially under unfavorable installation and utilization conditions.
It is therefore an object of the present invention to further develop a process of the type referenced above, by simple means and, importantly, without requiring a load sensor.
If a vehicle, for instance, has at least one rear axle brake, in addition to, for instance, a front axle brake, the present invention can distribute the needed braking force among the brakes by assigning brake application energies to the brakes in accordance with predetermined allocation rules.
In this manner, the present invention makes it possible to obtain any desired braking behavior. It is possible, during brake actuation, that the present invention always maintains the brake application energies in a fixed relationship to each other, or that it applies one brake constantly, while it applies the other brake with only certain values of the variable magnitudes of the brake allocation rules. However, the desired braking behavior may consist of a brake application which produces even brake wear (wear-optimized brake application), or of a brake application which avoids the swerving of a vehicle during braking (stability-optimized brake application), or of a combination of these two applications. The previously mentioned process, according to U.S. Pat. No. 5,338,106, provides such a combination. This process applies the brakes in a wear-optimized manner for lower deceleration demand signals, and in a nearly stability-optimized manner for greater deceleration demand signals. The limitation "nearly" is necessary because, as is discussed in detail in U.S. Pat. No. 5,338,106, a combination of wear-optimized and ideal stability-optimized brake applications is not possible.
The present invention can also be developed further to enable adapted utilization of a trailer brake.
The term "braking energy" should not be considered strictly in the physical sense, but as a collective term for all physical phenomena which cause a brake to produce a braking force. Electrical parameters, such as current and voltage, or mechanical parameters, such as pressure, can also be considered as types of braking energy. When pressure is used for braking energy, fluid or gaseous pressure means, e.g., compressed air, are normally used as the braking energy.